General Physics behind Resistive Touchscreens

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Basic Structure:

Two thin layers are coated with conducting material, Indium Tin Oxide(ITO).  Then they are separated by a small gap and are applied voltage.


The top layer is flexible, so when it is pressed down, it touches the bottom layer as shown in the figure to the right. 

By touching the bottom layer, it closes an electr circuit between the two conducting layers. The voltage resulting from the new formed circuit is measured and then with the help of complex software, the X, Y coordinates of the touch are calculated and registers the requested input

 



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      Rp is the resultant resistance from the pressure of the touch, 
                   which connects the two layers.


Note:  Even in resistive technology, there are different types of it. Depending on the type, the design and the detecting techniques may change. Visit the following link if you'd like to know more about different types of resistive technology. http://www.touchscreenguide.com/touchscreen/res.html#5w